The confrontation began in 2017 when the CBI issued a notice to the commissioner of Kolkata Police, Rajeev Kumar, in an investigation into the chit fund cases which was being handled by Asthana. This was followed up by a petition by the CBI in the SC alleging “non-cooperation” from the state police.

The CBI sent three summons to Kumar, who said the action was “politically motivated”. He also wrote to then director Verma in October 2017 stating if a “commissioner of police is served with notices under 160 of CrPc in cases which were supervised by him without even trying to make basic correspondence or ascertaining the exact circumstance, is like opening a Pandora’s box”.

About a year after the first CBI notice to Kumar, the ED wrote a letter to the DGP alleging its officers were facing “harassment” from the state police. Now, the ED is considering legal action and is preparing to file a petition in the SC, sources said.

A senior official of Kolkata Police said: “The CBI and ED have always acted as agencies above law. There are certain rules which all agencies need to follow while investigating. If they look for cooperation from us, they too need to cooperate with us.” Referring to the turn of events on Sunday, he said CBI officials tried to enter Kumar’s residence. “They must have some documents. Nobody can enter the residence or office of the head of the force that way,” he said.

Pankaj Srivastav, the joint director of CBI, whose residence and office were encircled by Kolkata Police personnel following the failed CBI operation on Sunday, said it was not always necessary to obtain a warrant for examining a person to whom several notices were served. “Rule of law shall prevail,” Srivastav told ET before leaving for Delhi on Monday.

Meanwhile, the ED has written to the state home secretary, requesting him to direct two senior Kolkata Police officials, whom it suspects of having some crucial information about the deposit-taking scam, to appear before the investigators.

In the investigation being handled by Asthana, three summons were sent over the past year to police commissioner Rajeev Kumar, who said the CBI actions were “politically motivated”. It was also learnt from reliable sources in the central agency that, barring the CP, at least three senior police officials including a DG-ranked and two ADG-ranked officers quietly appeared before the investigating agencies. Kumar, instead, wrote to then director of CBI Alok Verma in October 2017 stating that if a ‘commissioner of police is served with notices under 160 of CrPc in cases which were supervised by them without even trying to make basic correspondence or ascertaining the exact circumstance, is like opening a Pandora’s box.’. Following the letters notices stopped for several months till Asthana visits Kolkata to take a stock of the investigation.